2006 GMC Sierra 2500 HD - Stock-Appearing
A 680hp LBZ That Dominates the Dirt and the Dragstrip
Thanks to Donnie Eskridge’s 2006 GMC Sierra 2500 HD sending nearly 700 hp and 1,300 lb-ft of torque to the pavement, it’s hard for him to resist a nice, smoky burnout from time to time.
You could say the sport of sled pulling came naturally for Donnie Eskridge. The first time he hooked his 2006 GMC to the sled he beat out 35 other trucks in the local Work Stock Class. Needless to say, he was addicted immediately. Fast-forward five years and the truck now sports a built engine and transmission, a host of suspension and steering mods -- and remains at the front of the pack. Even better…the 680hp, full-pulling Duramax can still tow, be daily-driven, and run 11s in the quarter-mile. “After pulling season is over, I drive it more,” Donnie told us. “And it’s a blast to drive on the street.”
With plans for big fuel and air, Donnie knew the factory LBZ would never hold up, so he turned to good friend and Illini Outlaw Diesel owner, Andrew Karker. The short-block was rebuilt using ARP main studs, forged Carrillo rods, factory LML pistons, and the popular 3388 cam from SoCal Diesel. The heads were ported and polished by Premier Engine Design, and then equipped with SoCal Diesel’s Beehive valvesprings and chromoly pushrods. ARP studs keep the heads from lifting. A Fluidampr damper lessens engine vibration and Kryptonite Xtreme motor mounts keep the Duramax from rocking back and forth.
The fueling equation employs an AirDog system feeding a 10mm Stroker CP3 from Motorsport Diesel, and Exergy Engineering 60-percent-over injectors. Airflow comes by way of a 72mm Garrett 4094 from Danville Performance, which breathes through an AFE intake. A Flex-a-lite dual electric fan system helps keep coolant temp in check and frees up additional horsepower.
Transmission work was also performed by the folks at Illini Outlaw Diesel, who replaced the factory clutches, frictions, and steels, and separator, pressure, and apply plates with upgraded versions from PPE. Power transfer from the engine through the six-speed Allison was left to a triple-disc torque converter from River City Diesel. A transfer case brace and pump rub kit from Merchant Automotive were also added for strength and reliability reasons. Transmission control module (TCM) and ECM programming is handled by DuramaxTuner.com via EFILive software, and a DSP5 switch allows Donnie to navigate between tunes. Thanks to a dyno tuning session at DuramaxTuner’s facility, the truck made 678 hp and 1,298 lb-ft of torque at the wheels.
Reinforcing the frontend for sled pulling duty is a Moog pitman and idler arm, along with the appropriate Cognito Motorsports brace for each. Tie-rod flex is eliminated thanks to a set of 304 stainless steel sleeves from PPE. Merchant Automotive adjustable suspension stops were added in the rear, and the traction bars, hitch, and receiver came from BigChevyHitch.com.
Thanks to the GMC’s inherently light curb weight, Donnie’s Sierra can weigh 7,200 pounds at the dragstrip or 8,250 pounds at the pulls by simply adding or removing weight and fuel. This flexibility allows him to maximize the truck’s performance no matter what surface it’s competing on. In fact, this is just about as far as you can take a streetable ¾-ton before going the furthest in the dirt and the fastest at the dragstrip is no longer possible. Having the best of both (polar opposite) worlds is hard to come by, but Donnie’s nasty LBZ makes it look easy.
After exhaust finds its way through the ProFab Performance headers and up-pipes, leaves the turbo, and flows through a 3-inch downpipe, it makes its final escape via the 7-inch miter-cut stack in the bed.